Ubiquinone biosynthesis by the microsomal fraction from rat liver

• Published in: BIOCHIMICA ET BIOPHYSICA ACTA: INTERNATIONAL JOURNAL OF BIOCHEMISTRY AND BIOPHYSICS Vol. 926; no. 1; pp. 70 - 78
• Main Authors: Kalén, A., Norling, B., Appelkvist, E.L., Dallner, G.
• Format: Journal Article Publication
• Language: English
• Published: Amsterdam Elsevier B.V 08.10.1987; Elsevier; North-Holland
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Cattle; Cell Fractionation; Fundamental and applied biological sciences. Psychology; Lipids; Liver - metabolism; Male; Mevalonate incorporation; Microsomes, Liver - metabolism; Mitochondria, Heart - metabolism; Other biological molecules; Rat liver; Rats; Rats, Inbred Strains; Subcellular distribution; Subcellular Fractions - metabolism; Submitochondrial Particles - metabolism; Ubiquinone - biosynthesis; Ubiquinone - isolation & purification; Ubiquinone synthesis; Ubiquinone synthesis; Rat liver; Subcellular distribution; Mevalonate incorporation; Vesicle; Rat; Liver; Rodentia; Lysosome; HPLC chromatography; Lipids; Biosynthesis; Microsome; Golgi apparatus; Absorption spectrometry; Vertebrata; Mitochondria; Mammalia; Ubiquinone; Distribution; Endoplasmic reticulum
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/0304-4165(87)90183-8

The distribution and biosynthesis of ubiquinone were investigated in vivo in rats and using liver slices. In addition to mitochondria, Golgi vesicles and lysosomes also contain large amounts of this lipid, and even the plasma membrane, peroxisomes and microsomes demonstrate easily measurable amounts. The spectral and chromatographic properties of microsomal ubiquinone were identical to those of its mitochondrial counterpart. When pentane was used to deplete beef heart submitochondrial particles of ubiquinone, NDH and succinate oxidase activities could be restored by reincorporation of microsomal ubiquinone. Injection of [ 3H]mevalonate into the portal vein of rats and incubation of liver slices with [ 3H]mevalonate and [ 3H]- and [ 14C]tyrosine demonstrated that labeling of mitochondrial ubiquinone was initially much lower than labeling of the microsomal lipid. Furthermore, intraportal injection of [ 3H]mevalonate resulted in the rapid appearance of labeled ubiquinone in the blood. These results indicate that ubiquinone is synthesized not only in mitochondria, but also on the endoplasmic reticulum of rat liver.